Three years ago I called 5th edition Dungeons & Dragons the least balanced of all D&D editions. While I am a lot less exasperated by the rules now, I still believe this is true. However at least for my own campaign I now also know how to better balance the system, and that without having to change the rules.

A level 1 fighter and a level 1 wizard are going adventuring together. Who is going to do better? The fighter has a 16 Strength and a greataxe, which gives him a +5 to hit modifier, dealing 1d12+3 points of damage on a hit. The wizard has a burning hands spell, dealing 3d6 damage on multiple opponents, no to hit roll required, but the monsters can roll a saving throw for half damage. He has a sleep spell that affects 5d8 worth of monster hit points. His other level 1 spells are similar in power, So in the first fight the wizard is very likely to make a much stronger appearance than the fighter. While the fighter kills 1 kobold every round, the wizard knocks out several in each of the first two rounds. However the wizard gets only 2 spell slots at level 1, plus a third once per day with arcane recovery.

A marathon runner and a sprinter are racing each other. Who is going to do better? The answer obviously depends on the length of the race. In a short race the sprinter has a clear advantage, but the longer the race is, the more likely the marathon runner is to catch up. The marathon runner in 5E is the fighter, or similar classes, while the sprinter is the wizard, or other classes with lots of burst damage. While fights in 5E are generally short, the rules are designed around an adventuring day of 6 to 8 encounters. That is 20+ combat rounds. Yes, the wizard is going to dominate 3 of them. But for the rest he is going to sit there and cast the fire bolt cantrip for straight 1d10 damage, while the fighter is still doing his 1d12+3 with the same attack bonus. If you plot the cumulative damage the fighter and the wizard deal over the adventuring day, at some point the fighter will catch up or surpass the wizard.

So is the system balanced? Unfortunately that depends now very much on the DM. Because it is the DM who ultimately decides the length of the race, how many rounds of combat each adventuring day has. Most people still think that the wizard is the far stronger class than the fighter. The 6 to 8 encounters per day rule isn't widely applied, and most people have less encounters before a long rest, which favors the wizard sprinter over the fighter marathon runner. And of course there is the psychology of people simply not remembering boring combat rounds in which everybody just did his base attack; the wizard dropping a bunch of monsters with one fell swoop is a lot more memorable and exciting.

This is why there are GMs. You structure all of your encounters based on the strengths and weaknesses of the party of players you are creating them for. You provide a challenge catered to them. It's an area where PnP RPGs will always excel, and MMORPGs will always struggle to emulate (if they care to even try).

MMORPGs can take a different approach, though, because there are many players, so they can pick a workable team from those available. And usually the adventures are optional. A better comparison might be single-player CRPGs.

There is also the consideration that killing more earlier is better in a fight. Maybe the fighter could eventually kill off all the enemies, but he is taking heavy damage that entire time. If the wizard kills 3 of 5 enemies in the first round before they even act, that is suddenly a very easy fight.

One common mistake is that the 'sprinter' and the 'marathon runner' are in competition, when in reality it is a relay race. The fighter and the mage complement each other to get to the goal; if a party is arguing on "who has been more useful" then the GM has probably messed up somewhere along the way, or has been too rigid to allow for opportunities for all party members to shine in their own way.

Part is the GM and part is the player(s) of the mage. They must make judicious use of the limited resources they have available. Their choices early in the campaign with limited resources help later in the game when they have more but only a couple of 'heavy hitting' resources (spells).

I agree. The "strike early to make the battle easier" only works if the whole challenge is that one battle. If the mage wastes his spells on the trash mobs and has only cantrips left for the boss mob, he isn't playing his class very well.

I feel that 4th Ed. D&D solved this issue quite effectively with the daily/per_round/anytime powers system, in turns of class balance, a least. Therefore I find it quite mind-boggling that they threw all that out completely and went back to is essentially the same design as the earliest edition, around 40 years ago. I'm aware 4th Ed. was unpopular with a lot of players for whatever reason. But was the powers system actually a problem? I think they'd gone too granular & detailed with the tactical combat. But they could have overhauled that and still kept a simplified but much more balanced system of special abilities between various classes. Instead of making people reluctant to play a low level caster, and or a high-level non-caster. 4th of course has its pacing/resting issues, but at least all the classes are largely in the same boat.

@Perkus: Personally I love 4e for its very tactical combat. But I also have to agree with the main reason people give me for disliking 4e. All classes play the same. The only difference between them are the flavors on the powers, but the gameplay is pretty much all the same.

So yea, I think the power system was simultaneously the best and the worst thing of 4e.

@Caldazar That's interesting, about in 4th them all playing the same. I don't think I would agree, but I guess there is a lot more homogeneity than D&D ever had before. I haven't actively played either edition in something like a decade now, so I don't have a good sense what people disliked about 4th. If I went back, I think I'd have a hard time playing 5th knowing what they dumped from 4th.